Method of treating ingots.



nnirnn sra'rns rarnnr orrrcn.

HIRAM W. I-IIXON, 0F AIRE IrIBRE, MEXICO.

METHOD OF TREATING INGOTS.

inonsae.

To all whom it may concern:

Be it known that I, I-IIRAM W. HIXoN, a citizen of the United States, and a resident of Aire Libre, in the State of Puebla and Republic of Mexico, have made certain new and useful Improvements in Methods of Treating Ingots, of which the following is a specification.

My invention relates to methods of treating ingots, my more particular purpose being to so produce the ingots as to avoid the formation of blow holes and to render the metal dense, smooth and readily adapted for rolling.

As is well known in this art, metals such as steel, when melted and formed into ingots, absorb large quantities of air and other gases, and during the act of solidifying, the gases are expelled. The result is that the ingots are aptto contain numerous blow holes and the top surface ofthe ingot is frequently of a spongy character.

Sometimes ingots, after being cast, and before cooling, have been subjected to intense pressure for the purpose of expelling gases and rendering the ingots dense. This method, however, as generally employed, has the disadvantage that the molds containing the ingots are'subjected to intense heat and great pressure at the same time, the result being that the up-keep of the molds is rendered comparatively difficult and unduly expensive. What I seek to do, therefore, is to produce comparatively dense and solid ingots without subjecting the ingot mold to conditions unduly destructive. In doing this I employ, in treating the same ingot, two molds which are used in succession; first a mold made of cheap material and adapted to stand a high degree of heat alone; second, a tough and strong mold capable of standing considerable pressure when the mold in question is not subjected to excessive heat.

Reference is made to the accompanying drawings forming a part of this specification, and in whichlike letters indicate like parts.

Figure 1 is a view partly in elevation and partly in section, showing a hydraulic press and movable car associated therewith for carrying out my process. Fig. 2 is a view partly in elevation and partly in section showing the hydraulic press together with the steel mold for squeezing an ingot. Fig.

3 is a fragmentary section showing the Specification of Letters Patent.

Application filed September 8, 1913.

Patented June 3%), 1914.

Serial No. 788,768.

prints of the ingot while said ingot is being A squeezed in the hydraulic press. Fig. 1 is a section through an iron mold containing an ingot and adapted to withstand the heat thereof. Fig. 5 is a section through a steel mold used for holding the ingot while the latter is being subjected to hydraulic pressure.

A tramway is shown at 6 and a car 7 is movable upon this tramway. At 8 .are

shown cast iron molds in which the ingots are cast. Each of these molds is provided with a central space 9 for holding the metal of which the ingot is formed. Each cast iron mold 8 is provided with a lug 10 to facilitate handling the mold and its con-- tents. At 11 is a mold having the same general form as the mold 8, but made of tough steel rendered as strong as possible and adapted to withstand enormous pressure provided the mold is not unduly heated. An

the hydraulic press can be understood from Figs. 1 and 2. Two massive standards 14 are surmounted by a cross plate 15 so as to form a strong gallows frame. Secured to the standards 14; and located between the latter are two seats 16 of massive construc-:

tion, these seats extending slightly from the frame, as indicated in Fig. 1. Resting upon the seat 16 are guides 17, each being of sub s-tantially wedge shape in cross section as indicated in Fig. 1. Below the seats 16 is" a hydraulic cylinder 18, the water compartment being shown at 19. The cylinder 18 is secured rigidly to the standards 14: and is closed at its bottom by a head 20 held in position by bolts 21. Water pipes are shown:

at 22, 23 and a piston appears at 24:. When water is admitted through the pipe 22, the

- piston is forced upwardly, any water above the piston making its escape through the pipe 23. When water under pressure is admitted through the pipe 23, the piston 24 is forced downwardly, the water below it making its escape through the pipe 22.

Connected with the piston 24 is a plunger 25 which extends through a stuffing box 26 and carries a ram 2(. Several of these rams, varying slightly in maximum diameter, may be employed one at a time so as to adapt the press to ingots of different sizes. For this purpose each ram 27 is detachable relatively to the plunger 25. A massive bar 28 made of metal is provided with a hook 29 for engaging the lugs 10, 13, and pushing the molds 11 into difi'erent positions. A top plate 30 is adapted to fit over the steel mold l1 and under the plate 15. This top plate is employed as a stop against which the heated metal of the ingot lodges and is crowded when the ingot is subjected to pressure. The cast iron mold 8 and the steel mold 11 are slightly difierent in size. That is to say, the internal dimensions of the cast iron mold 8 when heated are approximately the same as the internal dimensions of the steel mold 11 when cold. The purpose of this arrangement is three fold; (1) to enable the steel mold, though cold, to be easily slipped over the hot ingot; (2) to virtually increase the strength of the steel mold by allowing it to be used when cold, for purposes of compressing the ingot, and (3) to enable the steel mold, by its subsequent expansion as it becomes slightly heated, to strip itself clear of the ingot.

I will now explain how the apparatus above described is used in carrying out my methods. A number of the cast iron molds 8 are placed upon the car 7 and are filled with molten metal, say steel. After the ingots become solidified superficially, and while each of them is still fluid internally that is, after each ingot acquires a solid skinthe molds are lifted up and thus stripped off of the ingots. This is done so as to leave the ingots standing upon the car, the ingots of course being treated one at a time. A mold 11 is now placed over each ingot. In doing this the mold 11 is placed in the hydraulic press, as indicated in Fig. 2, the top plate 30 being placed over the mold. The hydraulic pressure being now applied, the plunger 25 forces the ram 27 against the lower end of the ingot 12. The result is that the ingot is compressed from its lowermost portion upwardly as indicated at 12 in Fig. 2, the top of the ingot being forced against the top plate 30. This step takes place, it will be understood, before the ingot becomes thoroughly solidified and while its top portion, if not molten, is at least at a temperature as high as the welding point. Under the intense pressure the ingot is rendered solid throughout, its extreme upper portion being freed of blow holes and air bubbles and the texture of the steel being rendered close.

The steel mold 11, being cold at the start, gradually becomes heated as the ingot cools. By the time the ingot acquires its final form, as indicated in Fig. 3, the steel mold 11 acquires such a temperature as by its expansion to cleave away from the ingot. This leaves the ingot free, and by reversing the direction of the water through the pipes 22, 23, so as to lower the piston 24 and the ram 27, the ingot is lowered so as to rest upon the seats 16. In doing this the mold 11 descends slightly and also rests upon these seats. The ingot, being slightly conoidal in form, when once let down so that its base coincides with the base of the mold 11, is entirely discon nected from the mold. By thus compressing ingots, one at a time, each in a mold 11, any number of these molds can be left in different presses distributed along the track, or they may be pressed in the press one at-a. time and after being squeezed, taken back upon the same car from whichthey were removed. If desired, they may be transferred to the press from one car and afterward I loaded on another car.

I attach considerable importance to the slight difierence in size between the cast iron mold 8 and the steel mold 11. It is desirable that the steel mold 11 when cold, shall have the same dimensions, or at least the same in ternal dimensions, as the cast iron mold 8 when the latter is heated by the ingot. This means, of course, that the steel mold is slightly larger internally than the iron mold, if both molds be at the same temperature.

I do not limit myself to the particular apparatus shown, as my method may be carried said first mentioned mold is heated, and

squeezing said ingot within said second mentioned mold.

2. The method herein described of preparing dense ingots which consists in castin the ingot in a mold, stripping said mold from the ingot, placing a second mold upon the ingot, said second mold having, when cold, approximately the same internal di mensions as said first mentioned mold when said first mentioned mold is heated, squeezing said ingot within said second mentioned mold, and stripping said second mentioned mold from said ingot by aid of the expansion of said second mentioned mold by heat derived from said ingot.

3. The method herein described of preparing ingots which consists in casting an ingot in a cast iron mold, transferring said ingot thus cast into a steel mold, said steel mold when cold, being large enough to contain the ingot, subjecting said ingot while still hot and contained within said steel mold to the action of intense pressure, and ing said ingot while in said mold of larger stripping said steel mold from said ingot by size to intense pressure, and finally stripping aid of expansion of said steel mold due to said mold of larger size from sa d ingot by heat received thereby from said ingot. aid of expansion of said mold of larger size 5 4. The methodh hfirein described of piedue to heat, which it derives from said ingot. 15

paring ingots W ic consists in providing two molds of slightly different sizes, casting HIRAM HIXON' the ingot in the mold of smaller size, trans- Witnesses: ferrin'g the ingot to the mold of larger size, THos. HUNT; 10 said mold of larger size being cold, subject- A. MEDINA;

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of fatents, Washington, D. G. 

